Centrifugal amalgamator



March 13, 1934. w. J. REILLY 1,951,108

CENTRIFUGAL AMALGAMATOR Filed July 12, 1950 3 Sheets-Sheet 2 March 13,1934.

W. J. REILLY CENTRIFUGAL AMALGAMATOR Filed July 12 1950 glaflq rm 2 U55%? 5 Sheets-Sheet 3 awe/whom Patented Mar. 13, 1934 UNETEEE STATESPATENT QFFICE 1,951,108 CENTRIFUGAL AMALGAMATOR William J. Reilly,Denver, 0010. Application July 12, 1930, Serial No. 467,531 3 Claims.(01. 209--199) This invention relates to improvements in cenparticleswill be moved outwardly by the centrif trifugal amalgamators of the typeemployed for ugal force and come in contact with the mercury therecovery of metals from ore and is designed surface and since there is agreat afiinity between more particularly for use in recovering the regalmercury and the precious metals, the latter will 5 or precious metals,platinum, gold and silver, but be absorbed by the mercury and combinewith it 60 which may also be used for separating any metals to form anamalgam. It is evident that unless that will amalgamate with mercuryfrom nonsome means is provided for producing a circulametallic materialsand from metals that will not tion or fiow of mercury when the machineis in amalgamate with mercury. operation, the action will very soon slowdown It is well understood that since gold, silver and because after themercury has absorbed a quantity 65 platinum have a high specificgravity, they will of metal, it is not so efiective as clean mercurysettle to the bottom if they are present in a and I have thereforeprovided means for producliquid pulp which has been agitated and whichis ing a circulation of the mercury for the purpose of then allowed tostand for some time and be submaintaining the operation of the device atmaxijected to the action of gravity. Where the gold, mum efficiency atall times. 70 silver and platinum particles are very small, the Havingthus briefly described the invention the differential action due togravity alone, is not sufsame will now be described in detail, and forthis ficiently greater in reference to one of these mepurpose, referencewill be had to the accompanytallic particles than in reference to aparticle ing drawings in which the preferred embodiment of silica or anyother nonmetallic pulp material, of the invention has been illustrated,and in and separation in this manner has theretofore not which: provedsuccessful. Fig. 1 is a side elevation of my improved amal- It is wellknown that if materials are introduced gamating device, portions thereofbeing shown in into a centrifugal machine and rotated at a very section;

high velocity about a central axis, the force known Fig. 2 is atransverse section taken on line 2-2, 80

as centrifugal force is set up which is many times Fig, 1; greater thanthe force of gravity and advantage Fig. 3 is a section showing aslightly modified has therefore been taken of this knowledge to form ofconstruction of the bowl; effect separation of materials havingdifferent Fig. 4 is a view similar to that shown in Fig. 1,

densities such as cream and milk, which is a well but showing anotherembodiment of the inven- 8 known example, and for the separation ofmetals tion;

from nonmetallic particles held in suspension in Fig, 5 is a diametricalsection through a slightly a liquid. modified form of bowl;

This invention, briefly described, consists of a Fig. 6 is a Section ofportion of t 1 bowl which is Open at the top and which is of Fig. 5showing the same to a larger scale; mounted for rotation about avertical axis. Fig. 7 is a Section through the upper portion Means isProvided for rotating the bowl at a Very of a bowl of a slightlydifferent construction; high velocity and for introducing pulp into theand 40 gigg g f i gggi i figi g gfi i g ggfi fi Fig. 8 is a sectiontaken on line 8-8, Fig. '7. when the latter is rotated at a high speed,the' In the drawmgs referenie numeral 1 mercury will move outwardlytowards the walls of base member from Whlch two or more Velticalsupports 2 extend upwardly. The upper the bowl and will move upwardly,due to the fact ted at a high velocity, its ends of the supports areconnected by means that when a liquid is rota of a transverse bar 3, andanother s1m11ar bar 100 upper surface will assume the shape of a para- Iboloid of revolution. The characteristic of the 4 extends between theSupports a Short distance parabola will vary with the speed and if t iabove the top of the base. Where two vertical high, the inclination ofthe sides to the axis of pp are used, the transverse ba s 3 and 4 theparabola will be very small, with the result may be straight, but inactual practice at least that if asufiicient quantity of mercuryisemployed, three vertical supporting members are used and V the entireinner surface of the bowl can be covered the transverse supportsindicated in the drawwith mercury when the bowl is rotated. If pulp ingsby reference numerals 3 and 4 are then is introduced into the bowl nearthe bottom theremade with three radial arms spaced one hundred of, andcaused to rotate with the bowl, the pulp and twenty degrees apart Sinceth invention will flow outwardly and upwardly and the heavier is notconcerned with a specific shape or con- 1 10 struction of the support,the latter has been shown more or less diagrammatically.

Mounted for rotation in the frame above described, is a bowl comprisinga cylindrical or substantially cylindrical portion 5, whose lower endhas an outwardly extending flange 6 that is secured to the flange 7 atthe upper edge of the concave bottom part 8. The upper end of the member5 is curved inwardly and downwardly as indicated by reference numeral 9.Secured to the lower surface of member 8 is a shaft 10 that is held tomember 8 by means of a flange connector 11, or in any other suit ableway. The lower end of shaft 10 has a thrust bearing 12 and where itpasses through the horizontal member 4 it is provided with a ballbearing13. A belt pulley 14 is secured to shaft 10 between the two bearingsjust described. Secured to the upper surface of flange 9 is a spiderhaving a number of arms 15 that are downwardly and outwardly inclined inthe manner shown in Fig. 1. The upper ends of arms 15 terminate in acylindrical tubular portion 16 that forms a journal and which isrotatabiy mounted in the bearing 17 in member 3. When power is suppliedto the pulley 14 by means of a belt the bowl can be rotated at any speedin a manner quite apparent from the drawings.

Secured to the bottom 8 and extending upwardly in a pipe 18, whose axiscoincides with the ax1s of rotation, and which is provided near itsbottom with openings 19. Extending outwardly from pipe 18 are blades orfins 20. A pipe 21 is .secured to the upper transverse frame member '3by means of a bracket 22 and extends to a point within the pipe 18 asshown in Fig. 1. The upper end of pipe 21 is connected with a hopper 23that is adapted to contain liquid pulp ,and a valve 24 is providedbetween the hopper 40 outer surface of the bowl.

23 and pipe 21 for the purpose of regulating the flow of pulp.Surrounding the upper end of the bowl is a plate 25 that extendsdownwardly a short distance and is spaced from the A launder 26 surrounds the upper end of the bowl and has an upwardly extending flange orside 27 that pro- J'ects into the space between the member 25 and theouter surface of the bowl, and which is inclined and terminates in alaunder 28 that conveys the pulp to a dump. A pipe 29 provided with avalve 30 is secured to the bottom of the bowl and can be used fordraining the mercury.

Let us now assume that the bowl contains a quantity of mercury and thatit is rotated at a high speed. Since the mercury is contained in thebowl, it will naturally rotate with the bowl and after it has attained acertain speed of rotation, the action of the centrifugal force andgravity will arrange the mercury in such a way that the inner surfacethereof will follow the dotted line 31 which is a parabola. By properlyproportioning the amount of mercury to the size and the speed of thebowl, it is possible to make the mercury cover the entire irfner surfaceof the bowl and to ascend until it comes in contact with the undersurface of the inwardly and downwardly inclined flange 9. Since it isthe object of my invention to produce a circulation of the mercury, Ihave provided means for removing mercury from the top and returning itto the bottom of the bowl. This means consists of two or more arms 31that are secured to the pipe 21 and which extend upwardly along theunder surface of flange 9 as indicated by reference numeral 32 and havetheir ends termihating adjacent the inner surface of the bowl. Since thearms 31 are stationary, they will remove mercury from the sides of thebowl and stop its rotation, thereby permitting it to return in themanner indicated by the arrow. In Fig. 3, I have shown how the bowl canbe provided with a groove 33 near its upper end so that the mercury willaccumulate to a greater depth at this place, and this will facilitatethe operation of the arms 32.

In Fig. 7, among other things, I have shown a slightly modified form ofmeans which consists of arms 31d that are tubular, and which terminateat their outer ends in blades 32a that extend into the groove 33. Theinner ends of arms 3111 are provided with openings on their undersurfaces and with spouts 34 that direct the mercury into the pipe 18.When the arrangement shown in Figs. land 3 is employed, the mercury thatis removed from the side of the bowl will very quickly be made to rotatewith the pulp and it sometimes happens that it will not reach the bottomof the bowl, whereas, if it is returned to the pipe 18, it willinvariably reach the bottom of the bowl so as to produce a circulationof all the mercury whenever the machine is in operation.

Referring now more particularly to Figs. '7 and 8, it will be seen thatthe inner surface of the bowl has been provided with vertical grooves 35through which the mercury flows upwardly. One advantage of thesevertical grooves is that they prevent the mercury from lagging behindthe bowl and in this way the mercury is forced to rotate at the samespeed as the bowl, whereas, if the inner surface of the bowl is smooth,there is a slip between the mercury and the bowl and the former neverattains the speed of the bowl which is objectionable in devices of thistype because the mercury is required to flow upwardly along the steepwalls and should therefore have the greatest rotary speed possible underthe circumstances.

In Figs. 5 and e, I have indicated another modification that differsfrom the one shown in Fig. l in this, that the inner surface of the bowlis provided with depressed areas 36 into which the mercury gathers whenthe bowl is rotated. Any excess mercury accumulates in the groove 3'7 atthe top of the bowl. In the modification shown in Fig. 6, the mercurydoes not circulate when the machine is operating, but the heavierportions of the mercury or that part of it that contains the amalgam,becomes heavier, and moves outwardly and assumes the position indicatedby reference numeral 38, and this leaves the inner surface of themercury quite clean and free from amalgam.

In Fig. 4 I have shown another modification in which mechanical meanscomprising a pump 39 is used for returning the mercury to the bowl so asto effect a positive circulation of the mercury at all times. In theembodiment shown in Fig.4, the flange 9 of the bowl is dispensed withand the upper end of the bowl is provided with a downwardly extendingflange 25a and a mercury launder 40 that has one side 41 projectingupwardly in the space between theflange 25a and the outer surface of thebowl. A ring 42 extends downwardly into the bowl and terminates a shortdistance below the top thereof, and the upper edge of this ring isconnected with an annular plate 43 whose outer edge is secured to theupper end of the cylindrical ring 44. The outer surface of ring 42 isspaced a short distance from the inner surface of the bowl so as toprovide an annular space through which the mercury may pass on its wayto the launder 40. When the machine is operating the ring 42 serves toseparate the pulp from the mercury and the wings 45 function to stop therotation of the pulpas it flows outwardly in the direction of the arrows46. The pulp is directed into the launder 47 by the walls 48 and 49, andfinally passes through the conduit 50 to a dump. When the machine isoperating the pump 39 functions to remove mercury from the launder 40and to force it through the pipe 51 into the pipe 21 from which itpasses into the interior of pipe 18 and out through the holes 19 andthence upwardly along the wall of the bowl. With the machine justdescribed, a large quantity of mercury can be utilized and the machinecan therefore be operated for a long time as it will take much longer tomake the mercury so rich with metal that it will not circulate than whenthe smaller amount of mercury is used as in the other embodiments. Withthe construction shown in Fig. 4, it is also possible to effectcontinuous operation because the loaded mercury can be withdrawn throughthe pipe 52 and fresh mercury introduced and in this way the loadedmercury can be removed from the machine without stopping it.

The vanes 20 rotate with the bowl and naturally tend to impart to thepulp the same speed of rotation as that of the bowl, but since the edgesof these vanes do not extend to the inner surface of the bowl, there isa considerable slip between the bowl and the pulp and the lattertherefore travels upwardly in a helical path, which is advantageous forthis reason that it gives the centrifugal force a longer time to operatefor the purpose of effecting a separation of the metal values from thenonmetalliferous particles of the clip.

It will be seen from the above description and from the drawings that inmy improved machine, the mercury is constantly circulating and movingupwardly along the sides of the bowl and in this manner clean mercury isalways provided for coming in contact with the metal in the pulp andtherefore a highly efficient separation is maintained at all times.

Having described the invention what I claim as new is:

1. In a centrifugal amalgamator, in combination, a frame, a bowl securedto the frame and mounted for rotation about a substantially verticalaxis, the bowl being open at the top, a ring carried by the frame andlocated within the open top and spaced a short distance from the innersurface thereof, a quantity of mercury in the bowl, means for rotatingthe bowl at a high speed whereby the mercury will be thrown outwardlyand pass upwardly along the wall of the bowl and whereby a portion ofthe mercury will flow out between the bowl and the ring, means fordelivering pulp to the center of the bowl near the bottom, and means forreturning the mercury to the bowl after it has passed through the spacebetween the bowl and the ring.

2. In a centrifugal amalgamator, in combination, a frame, a bowl securedto the frame and mounted for rotation about a substantially verticalaxis, the bowl being open at the top, a ring carried by the frame andlocated within the open top and spaced a short distance from the innersurface thereof, a quantity of mercury in the bowl, means for rotatingthe bowl at a high speed whereby the mercury will be thrown outwardlyand pass upwardly along the wall of the bowl and whereby a portion ofthe mercury will flow out between the bowl and the ring, means fordelivering pulp to the bowl near the bottom, means for returning themercury to the bowl after it has passed through the space between thebowl and the ring and inwardly extending flanges on the ring forretarding the rotation of the pulp.

3. In a centrifugal amalgamator, in combination, a frame, a shaftattached to the frame and mounted for rotation about a vertical axis, abowl secured to the upper end of the shaft, said bowl having a bottomand substantially cylindrical side, a pipe secured to the bottom andextending upwardly to a point near the top of the bowl, the pipe havingopenings at its lower end, a plurality of vanes secured to the pipe andextending radially to a point adjacent the inside of the bowl, a troughcarried by the frame and surrounding the upper end of the bowl, a flangecarried by the bowl and extending downwardly into the trough, an annularchannel shaped ring carried by the frame and enclosing the upper end ofthe bowl, the inside wall of the channel lying within the bowl andspaced a short distance from it and the outer wall extending into thetrough whereby a passageway is formed for the passage of mercury fromthe bowl to the trough, means for rotating the bowl, means fordelivering pulp to the inside of the pipe carried by the bowl and meansfor transferring mercury from the trough to the inside of the pipe.

WILLIAM J. REILLY.

